Implantable electrical stimulation systems have proven therapeutic in a variety of diseases and disorders. For example, spinal cord stimulation systems have been used as a therapeutic modality for the treatment of chronic pain syndromes. Peripheral nerve stimulation has been used to treat chronic pain syndrome and incontinence, with a number of other applications under investigation. Functional electrical stimulation systems have been applied to restore some functionality to paralyzed extremities in spinal cord injury patients.
Stimulators have been developed to provide therapy for a variety of treatments. A stimulator can include a control module (with a pulse generator), one or more leads, and an array of stimulator electrodes on each lead. The stimulator electrodes are in contact with or near the nerves, muscles, or other tissue to be stimulated. The pulse generator in the control module generates electrical pulses that are delivered by the electrodes to body tissue.
Delivering drugs at a specific site, such as in proximity to neural tissue in the spine or brain, can be used for treating a number of different indications, as well as for providing gene therapy. Additionally, site-specific delivery of drugs may reduce the amount of the drug needed for obtaining efficacious treatment, as well as reducing potentially adverse side-effects caused from uptake of the drugs at other, undesirable locations within the patient. Photonic stimulation may also be used for treating a number of different indications. Additionally, photonic stimulation may be used in combination with site-specific drug delivery. For example, optogenetics is a field where light is used to control neural activity in combination with drug delivery.